The invention relates to a process for the production of a deposit of inorganic nanoparticles having micro gaps onto a light-transparent support as well as a deposit that can be obtained by the process.
Within the framework of the invention “deposit of inorganic nanoparticles having micro gaps” is understood to be a deposit of inorganic nanoparticles that have cavities of micrometric size forming “domes”, for example, that are possibly interconnected depending on the form of deposit. The size of the nanoparticles typically ranges between 5 and 50 nm. The shell of each base cavity or “dome” is therefore formed from at least one layer of inorganic nanoparticles. Moreover, there can be gaps or spaces between each base nanoparticle, referred to here as “nano gaps”.
Patent US 2007/0104922 describes a process for the production of a deposit formed from several layers of inorganic nanoparticles secured to a light-transparent support by means of an organic polyelectrolyte. The deposit can be applied to all the faces of the support provided that it is possible to immerse said deposit in the aqueous preparation solution. It gives the support antireflective properties, but no experimental element is provided to show that the diffusion of the light is affected by the deposit. It also has good wettability properties (superhydrophilicity or, for the formation of a supplementary chemical deposit, superhydrophobicity).
Light transmission values of above 99% for incident light in the visible range (400 to 800 nm) are indicated in this patent application. The optimum performances obtained are 99.7% light transmission (92% for a normal glass) and 0.1% light reflection (8% for a normal glass).
There is an ongoing need in the field of layers on transparent supports to improve the diffusion of light in particular in the visible range as well as improve the antireflective properties of such supports.